Bioreactors, which are also frequently referred to as fermenters, enclose a reaction chamber in which biological or biotechnological processes can be carried out on a laboratory scale. Such processes include, for example, the cultivation of cells, microorganisms or small plants under defined, preferably optimized, controlled and reproducible conditions. Bioreactors mostly have a plurality of connectors via which the primary and secondary substances, as well as various instruments, such as sensors, can be introduced to the reaction chamber or to which fluid conduits, for example, in particular gas conduits such as gassing conduits or exhaust gas conduits, can be connected. In addition, bioreactors generally include a mixer, the shaft of which can be made to rotate by a drive, as a result of which a stirring member connected torsionally rigidly to the mixer shaft is likewise made to rotate, thus mixing the substances present in the reaction chamber. It is also possible for two or more stirring members, mostly spaced axially apart, to be arranged on and connected to the mixer shaft. The stirring member or stirring members may also be integral with the mixer shaft.
Bioreactors are preferably used in bioreactor systems, preferably in parallel bioreactor systems, not only in the field of cell cultivation but also in microbiological applications. Parallel bioreactor systems are described in DE 10 2011 054 363.5 and DE 10 2011 054 365.1, for example. In such bioreactor systems, a plurality of bioreactors can be operated in parallel and controlled with higher precision. High-throughput experiments that are well reproducible and scalable can be carried out in the individual bioreactors, even with small operating volumes. The laboratory scale of the bioreactors to which the invention relates involves volumes of up to 2000 ml, or more specifically with a total reaction chamber volume of approximately 350 ml, with a working volume ranging between about 60 ml and about 250 ml.
In the cell culture field, such parallel bioreactor systems are used, for example, for test series for process optimization based on statistical planning methods (design of experiments DoE), for process engineering and in research and development, for example to cultivate different cell lines such as Chinese hamster ovary (CHO), hybridoma or NSO cell lines. In the context of the present application, the expression “cell culture” is specifically understood to mean the cultivation of animal or plant cells in a nutrient medium outside the organism.
In the field of microbiology, parallel bioreactor systems are likewise used for test series for process optimization based on statistical planning methods (design of experiments DoE), for process engineering and in research and development, for example to cultivate various microorganisms, in particular bacteria or fungi, such as yeast.
Due to limitations of space in most laboratories, minimal space requirements and in particular small footprints are striven for, not only for bioreactor systems but also for the bioreactors themselves.
Bioreactors used in laboratories are often made of glass and/or metal, in particular of stainless steel, as the bioreactors must be sterilized between different uses, preferably by steam sterilization in autoclaves. Sterilizing and cleaning reusable bioreactors is a complex process. The sterilization and cleaning process can be subject to validation, and needs to be precisely documented for each individual bioreactor. Residues in a bioreactor which has not been fully sterilized can falsify the results of a subsequent process, or render them useless, and may cause disruption of the subsequent process. Furthermore, the sterilization process may also expose Individual components or materials in bioreactors to stress and strain, and in some cases can damage them.
Single-use bioreactors provide an alternative to reusable bioreactors and are used to carry out just one biological or biotechnological process before being disposed of. By providing a new single-use bioreactor for each process, and one that is preferably sterilized during the production process, it is possible to reduce the risk of (cross-)contamination, while simultaneously obviating the need to perform and document the impeccable cleaning and sterilization of a previously used bioreactor. Single-use bioreactors are often designed as flexible containers, for example as bags, or as containers having walls that are flexible in sections thereof at least. Examples of such bioreactors are described in US 2011/0003374 A1, US2011/0058447A1, DE 20 2007 005 868U1, US 2011/0058448A1, US2011/0207218A1, WO 2008/088379A2, US 2012/0003733 A1, W02011/079180A1, US2007/0253288A1, US 2009/0275121A1 and US 2010/0028990A1. However, one disadvantage of these single-use bioreactors with flexible walls, inter alia, is that they cannot be used in parallel bioreactor systems, which are designed for dimensionally stable, reusable bioreactors.
Further, for reasons of scalability of processes to different scale, qualitative comparable and particularly defined fluid dynamics (particularly during stirring) in the cultivation chamber are important, This requirement cannot be realized with bioreactors with flexible walls or can be realized only with extensive additional measures.
Dimensionally stable single-use bioreactors are known from EP 2 251 407 A1 and from US 2009/0311776 A1, for example. Examples of dimensionally stable single-use bioreactors available on the market include the Celligen Blu, the Millipore Mobius and the Sartorius UniVessel. However, these known, dimensionally stable single-use bioreactors are high-priced, on the one hand, and on the other hand are designed for pharmaceutical process engineering and pharmaceutical production processes. These are used for cell culture processes, in particular, and are therefore specifically designed and adapted for such cell culture processes. Different requirements must be met for applications in microbiology, however, not only with regard to the prices that can be charged on the market, but also with regard to appropriate design and to the materials that can be used. Dimensionally stable single-use bioreactors known from the prior art are unsuitable, therefore, for use in microbiology research or in process engineering, for example.
The object of the present invention is therefore to provide an improved single-use bioreactor and a head plate, and to specify a manufacturing process that reduces or eliminates one or more of the aforementioned disadvantages. One object of the present invention, more specifically, is to provide an improved single-use bioreactor which is suitable for use in both cell culture and microbiology applications, and in particular for use in a preferably parallel bioreactor system. Other objects of the invention are to provide a single-use bioreactor and a head plate which are inexpensive to produce, and to specify simple and cost-efficient processes for manufacturing a single-use bioreactor and a head plate.